From fdfb1e4f6c61477a61890b64974d65cdc3a98702 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 10 Dec 2010 06:41:56 +0000 Subject: Btrfs: Make async snapshot ioctl more generic If we had reserved some bytes in struct btrfs_ioctl_vol_args, we wouldn't have to create a new structure for async snapshot creation. Here we convert async snapshot ioctl to use a more generic ABI, as we'll add more ioctls for snapshots/subvolumes in the future, readonly snapshots for example. Signed-off-by: Li Zefan Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 44 +++++++++++++++++++++++++++----------------- fs/btrfs/ioctl.h | 14 +++++++++----- 2 files changed, 36 insertions(+), 22 deletions(-) (limited to 'fs') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7cc2e8e..f87552a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -947,31 +947,41 @@ out: static noinline int btrfs_ioctl_snap_create(struct file *file, void __user *arg, int subvol, - int async) + int v2) { struct btrfs_ioctl_vol_args *vol_args = NULL; - struct btrfs_ioctl_async_vol_args *async_vol_args = NULL; + struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL; char *name; u64 fd; - u64 transid = 0; int ret; - if (async) { - async_vol_args = memdup_user(arg, sizeof(*async_vol_args)); - if (IS_ERR(async_vol_args)) - return PTR_ERR(async_vol_args); + if (v2) { + u64 transid = 0; + u64 *ptr = NULL; - name = async_vol_args->name; - fd = async_vol_args->fd; - async_vol_args->name[BTRFS_SNAPSHOT_NAME_MAX] = '\0'; + vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2)); + if (IS_ERR(vol_args_v2)) + return PTR_ERR(vol_args_v2); + + if (vol_args_v2->flags & ~BTRFS_SUBVOL_CREATE_ASYNC) { + ret = -EINVAL; + goto out; + } + + name = vol_args_v2->name; + fd = vol_args_v2->fd; + vol_args_v2->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; + + if (vol_args_v2->flags & BTRFS_SUBVOL_CREATE_ASYNC) + ptr = &transid; ret = btrfs_ioctl_snap_create_transid(file, name, fd, - subvol, &transid); + subvol, ptr); - if (ret == 0 && + if (ret == 0 && ptr && copy_to_user(arg + - offsetof(struct btrfs_ioctl_async_vol_args, - transid), &transid, sizeof(transid))) + offsetof(struct btrfs_ioctl_vol_args_v2, + transid), ptr, sizeof(*ptr))) ret = -EFAULT; } else { vol_args = memdup_user(arg, sizeof(*vol_args)); @@ -984,9 +994,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, ret = btrfs_ioctl_snap_create_transid(file, name, fd, subvol, NULL); } - +out: kfree(vol_args); - kfree(async_vol_args); + kfree(vol_args_v2); return ret; } @@ -2248,7 +2258,7 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_getversion(file, argp); case BTRFS_IOC_SNAP_CREATE: return btrfs_ioctl_snap_create(file, argp, 0, 0); - case BTRFS_IOC_SNAP_CREATE_ASYNC: + case BTRFS_IOC_SNAP_CREATE_V2: return btrfs_ioctl_snap_create(file, argp, 0, 1); case BTRFS_IOC_SUBVOL_CREATE: return btrfs_ioctl_snap_create(file, argp, 1, 0); diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 17c99eb..c344d12 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -30,11 +30,15 @@ struct btrfs_ioctl_vol_args { char name[BTRFS_PATH_NAME_MAX + 1]; }; -#define BTRFS_SNAPSHOT_NAME_MAX 4079 -struct btrfs_ioctl_async_vol_args { +#define BTRFS_SUBVOL_CREATE_ASYNC (1ULL << 0) + +#define BTRFS_SUBVOL_NAME_MAX 4039 +struct btrfs_ioctl_vol_args_v2 { __s64 fd; __u64 transid; - char name[BTRFS_SNAPSHOT_NAME_MAX + 1]; + __u64 flags; + __u64 unused[4]; + char name[BTRFS_SUBVOL_NAME_MAX + 1]; }; #define BTRFS_INO_LOOKUP_PATH_MAX 4080 @@ -187,6 +191,6 @@ struct btrfs_ioctl_space_args { struct btrfs_ioctl_space_args) #define BTRFS_IOC_START_SYNC _IOR(BTRFS_IOCTL_MAGIC, 24, __u64) #define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64) -#define BTRFS_IOC_SNAP_CREATE_ASYNC _IOW(BTRFS_IOCTL_MAGIC, 23, \ - struct btrfs_ioctl_async_vol_args) +#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \ + struct btrfs_ioctl_vol_args_v2) #endif -- cgit v1.1